Boston plans energy-efficient housing expansion

The initial four homes, which recently went up in Dudley Square and reportedly generate almost twice as much power as they consume, will be followed up by a development of 40 similar units in Mission Hill.

Energy savings are realized via the use of enhanced building materials, solar technology and double-thick insulation. However, solar equipment must be purchased or rented for an additional fee, and median prices are at $540,000, though the initial goal was to stay below $400,000.

Concerns over affordability are mitigated by the estimated $132 per month in utility savings, which would potentially pay for the investment in five or six years and allow homeowners to generate additional revenue thereafter, according to the Globe.

The energy-positive community will be the first in Mayor Menino's E+ Green Communities Program, a larger initiative to bring sustainable, regenerative buildings to Boston.